In recent times, coal has become a viable fuel for generating steam. Some coals include a high percent of sulfur, which will be released to the atmosphere in the form of hydrogen sulfide or sulfur oxide unless steps are taken to prevent this release. One means of preventing this SO.sub.x release to the atmoshpere which is presently being used is to add a sorbent, such as limestone, to the furnace, so that the sulfur combines with the calcium and magnesium to form solid sulfates. There are problems associated with this solution. The limestone must be added at the proper location in the furnace so that the limestone is not deadburned. Also, the limestone must be dispersed throughout the combustion gases such that it will come into intimate contact with and react with most of the sulfur compounds, an stay in contact for an extensive period of time, at the proper temperature (1700.degree.-2200.degree. F.), so that much of the sulfur will combine with the calcium and magnesium to form sulfates. To compound the problem of good distribution of the sorbent throughout the gas flow, if the load on the steam generator changes, and the firing of the furnace is thus varied, the flow pattern of the combustion gases can change.